A counter ejector part is provided in the most downstream part of a box-manufacturing machine for manufacturing cardboard boxes, which accumulates, counts, and stacks manufactured cardboard boxes in the form of sheet, and ejects them as a batch. In a counter ejector provided in the counter ejector part, cardboard boxes that are fed in the conveyance direction through a pair of upper and lower feed rolls, and advance into a hopper part (receiving space) are hit to a front stop (front stopper plate), and are allowed to fall by their self weights or a wind pressure provided by a blower. The fallen cardboard boxes are stacked on a stacking part in the hopper part (receiving space).
Some of such counter ejectors are provided with a squaring device that carries out squaring on cardboard boxes stacked on the stacking part, to eliminate distortions, e.g., fishtails, for rectifying the cardboard boxes into proper rectangular shapes. As disclosed in Patent Document 1, a squaring device includes a front stop, and a squaring plate (referred to as a rectification plate or a squaring bar, or sometimes referred to as a spanker since it spanks one end of a cardboard box) that is arranged facing the front stop and reciprocates in the directions approaching to or departing from the front stop. The squaring plate reciprocates at a predetermined cycle, and rectifies cardboard boxes fed and fallen to the stacking part, one by one while sandwiching them in conjunction with the front stop.
Furthermore, Patent Document 2 discloses, in an apparatus wherein cardboard boxes are slid by a conveyer belt under an ejecting and stacking part, from the upstream of the conveyance direction, thereby accumulating the cardboard boxes into a predetermined stack, a technique to rectify the shape of a cardboard box at the bottom of the stack sandwiched between a front stop and a squaring plate, by providing the front stop in front of the conveyance direction of the cardboard box at the bottom of the stack, providing the squaring plate facing the front stop, and reciprocating the squaring plate.